Closure for collapsible carton



www@

H. DROZDA CLOvSURE FOR COLLAPSIBLE CARTON 2 Sheets-Sheet l Filed Oct. 13, 1965 INVENTOR.

H. DROZDA CLOSURE FOR COLLAPSIBLE CARTON 2 Sheets-Sheet 2 Filcd 06+ 13, 1965 INVENTOR. QOZa/c? United States Patent Oice 3,3 lid@ Patented Apr. lll, lido? 3,333,469 CLGSURE FR CGLLAPSIBLE CARTGN Harry Dresda, Sill Ash St., Richmond, British Columbia, Canada Filed Get. 13, 1965, Ser. No. 495,646 9 Claims. (Cl. 229-33) This invention relates to an end closure for a collapsible carton formed from a foldable blank and to the method of forming the carton end closure to attain auto` matic engagement of the closure arrangement.

Heretofore, the art relating to foldable blank containers has proposed and utilized numerous designs of self locking closures but these have either required excessive manipulation of the iiaps to attain locking interengagement or they have required extra operations in manufacturing as, for example, the pre-application of adhesive or other connections between certain otherwise discrete closure portions, or nally these designs have afforded simplicity in manufacture and in the set-up operation but have been deficient in strength qualities to sustain relatively heavy articles in the cartons or have not been sufficiently resistant to distorting forces which might rack the container out of normal tubular wall formation.

Accordingly the present invention provides a carton with a foldable iiap closure which is simply die cut from a blank of foldable sheet material, for example corrugated paperboard, whereby the carton includes tubularly arranged side and end Walls with a pair of opposed liaps connected to the side walls and in partial overlapping relation to each other. One of said opposed iiaps is oldably connected to a pair of bellows fold extensions which are in turn foldably connected to the carton end wall panels and these bellows fold extensions are folded into flatwise relation to the exterior surface of said foldably connected one flap whereby the opposed flap may be interposed between portions of the bellows fold extensions in locking engagement therewith providing a closure of utmost facility in erection and with unusual strength properties for sustaining weights and resisting racking of the carton walls.

These and other objects and advantages of this invention will be apparent to those skilled in the art upon a full and complete understanding of the construction and operation of the invention by reference to the accompanying drawings and detailed description in which:

ln the drawings:

FIGURE l is a plan view of a foldable blank from which the carton may be formed;

FGURE 2 is a perspective view showing an initial stage of erection of the carton closure;

FIGURE 3 is a perspective view of a further stage in the erection of the carton closure;

FIGURE 4 is a perspective view of a nal stage in the erecting operation wherein the closure portions are depressed inwardly of the plane of the end of the carton walls;

FlGURE 5 is a perspective view of a completed closure with the carton closure portions in engaged relation;

FIGURE 6 is a perspective view of a stage of assembly of a container top closure arrangement embodying the invention;

FIGURE 7 is a perspective view of a further stage of assembly of the top closure just prior to complete engagement of the closure.

A blank 2G of ioldable material such as corrugated paperboard and embodying the invention is shown in FIGURE l. In the drawing, fold lines constituted by lines of scoring are indicated by interrupted lines and cut edges are represented by solid lines. The blank 2G described in terms equally applicable to the container formed therefrom comprises a series of alternating end and side wall panels 2li-24 foldably connected by corner scores 25-2'7. A connecting liap 23 is foldably connected to one wall panel 2 by corner score 29. The remote edge 3Q of the blank determines the remaining side edge of wall panel 2d. The top and bottom edges of the wall panels 2li-2d are determined by top flap line of scoring 3l and bottom liap line of scoring 32 respectively.

The bottom closure assembly 33 comprises an arrangement of aps foldably connected along flap score 32 to the respective wall panels 2l-24. This assembly 33 includes a pair of opposed tiaps 341-35 coextensive in breadth to the respective side wall panels 22 and 2d. The one opposed liap 34 is provided with end edges 36 defined by lines of scoring constituted by extensions of corner scores 25-26. The end edges 36 are thus in foldably connected relation to the pair of bellows fold mern bers 37-38 which are in turn foldably connected along liap score 32 to the respective end wall panels Zit-23.

A free edge 39 denes the extremity of the one opposed bottom tiap 34 and the bellows fold members 3'7-38 remote from bottom ap score 32. The bellows fold members 37-33 additionally each include angular fold lines il extending in bisecting relation from the intersection of bottom liap lscore 32 and respective end edge scores 36 and terminating at free edge points of abutment dit.

The angular fold lines lil determine a first portion 42 of each bellows fold member 37-3 adjacent to the one flap 34 and second portions 43 associated with the respective end wall panels 21 and 23. Free edges 44 extend from the free edge points of abutment 4i to the edge 39. Finally, edges 45 extend from the points of abutment iti to substantially the bottom corners of end wall panels Zit-23 remote from the one opposed flap 34.

The second one 35 of the opposed pair of flaps is deiined by end edges 46 and abutting free edge i7 remote from the liap score 32.

The top closure assembly 5b may be identical to the bottom closure assembly 33 as shown, but includes means for opening and reclosing a filled container, as described hereinafter. Such means includes a bendable portion Si of the first portions 4Z' of the bellows fold members 37- 8 dened by the free edges 39 and 44 thereof and fold lines 52 extending between the respective points of abutment il and free edge 3%'.

ContinuityT with the top closure assembly opening and reclosing means the second one of the opposed pair of top flaps 35 includes bendable portions 53 constituted by corner extremities thereof defined by angulated fold lines 54 as shown.

in the erection and utilization of the collapsible container embodying the end closure invention, the side and end wall panels are connected in foldable tubular relation Vby securing the connecting liap 28 to the remote Wall panel marginal edge 3i? by gluing or stapling the same or other conventional connecting means. in utilizing the container, the walls 2-24 are erected to tubular relation as shown in FGURES 2 through 5 inclusive. These livures are inverted to lmore clearly show the operation of folding and automatic interengagement of the bottom closure assembly 33.

Looking first to FlGURE 2 the second one 35 of the opposed pair of iiaps is first infolded and in generally perpendicular relation to its related side wall panel 24 and the bellows fold members 317-38 are moved Outwardly about the angular fold lines in and the one opposed iiap 3ft folded inwardly into partially overlapping relation to the second opposed flap 35 as shown in .EIG- URE 3.

Continuing with the folding of the bottom closure assembly 33, the bellows fold members 37-38 are infolded into liatwise relation with the one opposed iiap 34 and projected inwardly of the container luntil the free 3 edge 39 thereof moves past the abutting edge 47 of the second opposed flap 35 in the manner indicated in FIG- URE 4. Thus the edge 47 and adjacent margins of the second opposed llap 35 automatically snap into disposition intervening the first portions 42 and the second portions 43 of the respective bellows fold members 357-38 until the edge 47 abuts at least the points of abutment i1 along the angular fold lines 4t) to attain the interlocking, secured end closure as shown in FIGURE 5. It rnay thus be seen that there is a relation of the parts, arrangement and dimensioning of the parts of the bottom closure assembly 33 such that the distance between the bottom ap line of scoring 32 and the abutting edge 47 of the second one of the opposed flaps 35 relates to the dimension between the one iiap 34 flap score 32 and the point of abutment ffii in a manner to allow the interengaged closure assembly 33 to attain a substantially planar relation in end closing relation to the wall panels 21-24. It is also to be noted that the line of abutting Iengagement may be disposed along a middle longitudinal line of the container bottom or varied on either side thereof so long as there is an overlapping relation of the free edge 39 of the one opposed flap 34 and the abutting edge -47 of the second opposed flap 35 and the points 41 in the bellows fold members are in spaced relation from the free edge 39.

To disengage the bottom closure assembly 33 a reverse procedure is followed, that is, the assembly 33 is inwardly deflected within the container until the second opposed flap 35 abutting edge 47 clears from engagement between the bellows fold members 37-38 respective first and second portions of 42-43 whereupon the members 37-38 may be folded outwardly and the opposed aps 34-35 may be extended to substantially vertical 4planar relation with their respective wall panels 21-24. Thus, the interloclied closure assembly is resistant to disengagement by the pressure of contents within the container, ibut upon removal and emptying of the container contents the container closure is readily disengaged and the container collapsed for storage or return shipment without impairing the elements of the container construction whatever and without the use of extraneous tools or materials.

A similar closure assembly may be used for a top closure as shown in FIGURE 6. However, the top closure assembly Sii normally must be subject to interen- ,gagement and release from interengagement in a manner whereby it is not necessary to deflect the top closure assembly 59 within the confines of the container in view of the fact that normally the contents of the container will render this impossible. Therefore, bendable portions 5l determined by fold lines 52 are provided in the bellows fold members 3738 first portions 42. Additionally, bendable portions 53 determined by angulated fold lines 54 are provided in the second one of the opposed aps 35 as shown in FIGURE 6. To assemble this top closure assembly 50 the lbendable portions 53 of the second opposed flap 35 are inserted between the first and second portions 41-42 of the bellows fold members by the accompanying deection of the bendable portions 51 of the first portions 42' as shown in FIG- URES 6 and 7.

It is apparent that this top closure assembly may likewise be reopened by the simple lifting of the second opposed ap 35 to withdraw the flap from locking position intervening the first and second portions 42-43 of the bellows fold members of the top closure assembly 5t). While this interengagement of the top closure assembly 50 depends primarily on a frictional securement rather than the positive abutment and full utilization of the rigidity of the container board material which characterizes the bottom closure assembly 33, it is to be found that the locking engagement of the top closure assembly 50 is fully adequate to maintain the closure secured during all normal handling and shipping and yet afford the convenience of an openable and recloseable flap closure while maintaining the freedom from usage of extraneous tools and materials.

While the present description sets forth preferred embodiments of the invention, various changes may be made in the construction without departing from the spirit of the invention, and it is therefore desired that the disclosed embodiments be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than the foregoing description to indicate the scope of the invention.

What I claim as my invention is:

l. An end closure for a collapsible carton, the carton having tubularly arranged side and end wall panels with the end closure connected to one end thereof, the end closure including a pair of opposed flaps each foldably connected to a respective side wall panel and with free edges opposite the respective fold connections, said free edges being in overlapping relation, one of said flaps havinf7 end edges in foldably connected relation to a pair of bellows fold members which are in turn foldably connected to the adjacent end wall panels, the bellows fold members disposed in fiatwise exterior relation to said one fiap and including an angular fold line therein terminating at respective free edge points, the second one of said opposed pair of flaps disposed with marginal portions adjacent the free edge intervening the first and second portions of the bellows fold members to secure the bottom closure from outward extension.

2. An end closure for a collapsible carton, the carton having tubularly arranged side and end wall panels with the end closure connected to one end thereof, the end closure including a pair of opposed flaps and a pair of bellows fold extensions, the pair of opposed flaps each being foldably connected to a side wall panel and substantially coterminous in length therewith and having innermost edges opposite the respective fold connections in overlapping relation, one of said flaps havinge end edges in foldably connected relation to the pair of bellows fold members, the bellows fold members each disposed in fiatwise exterior relation to said one liap and including an angular fold line therein extending to a free edge of the respective member, the angular fold lines determining a first portion of each bellows fold member adjacent and foldably connected to the one Hap and second portions foldably connected to the respective end wall panel, the second one of said opposed pair of fi-aps having the innermost edge margin thereof disposed between said portions of the bellows fold extensions and abutting the angular fold line thereof.

3. An end closure as defined in claim 2 in which the second portions of the bellows fold :members in foldably connected relation to the end wall panels having free edges extending in angular relation from the free edge points to the fold connection between the end closure and the end wall panels.

4. An end closure as defined in claim 2 in which the second one of the opposed pair of iaps includes bendable portions adjacent the end edges thereof dened by angulated fold lines and cooperative bendable portions are defined in the subjacent bellows fold first portions to permit locking interengagement and disengagement of the end closure to and from a position outwardly extended from the collapsible carton tubular walls.

5. An end closure for a collapsible carton, the carton having tubularly arranged side and end wall panels with the end closure yhaving a fold connection to one end thereof, the end closure including a pair of opposed liaps each foldably connected to a respective side wall panel and with free edges opposite the respective fold connection, said free edges being in mutual overlapping relation, one of said fiaps having end edges in foldably connected relation to a pair of ybellows fold members which are in turn foldably connected to the adjacent end wall panels, the bellows fold members each including an angular fold line therein terminating at a free edge point, the angular fold lines determining first and second portions of each bellows fold member, the bellows fold members disposed in atwise exterior relation to said one flap, the second one of said opposed pair of flaps disposed with the free edge thereof in abutting relation to the .angular fold lines and with marginal portions adjacent the free edge intervening the irst and second portions of the bellows fold members to secure the bottom closure from outward extension.

6. An end closure as dened in claim 5 wherein the pair of opposed aps are each substantially coterminous in length with the respective connected wall panels and the end edges thereof are disposed in parallel adjacency to the interior surfaces of the end wall panels affording resistance to distortion from normal tubular relation of the wall panels.

7. An end closure as dened in claim 5 in which the second portions of the bellows fold members in foldably connected relation to the end wall panels having free edges extending in angular relation from the free edge points to the fold connection between the end closure and the end wall panels.

8. An end closure as dened in claim 7 in which the second one of the opposed pair of aps includes bendable portions adjacent the end edges thereof defined by angulated fold lines and cooperative bendable portions are delined in the subjacent bellows fold first portions to permit locking interengagement and disengagement of the end closure to and from a position outwardly extended from the collapsible carton tubular walls.

9. An end closure as delined in claim 5 wherein the pair of opposed flaps are each of rectangular conformation and present smooth rectangular surafces to the interior of the container.

References Cited by the Examiner UNlTED STATES PATENTS 288,255 11/1883 Munson 229-39 2,031,806 2/ 1936 Weiss 229-37 2,297,571 9/ 1942 Lowey 229-27 2,307,913 l/ 1943 Bergstein 229-39 2,875,943 3/1959 Cooper 229-39 GEORGE O. RALSTON, Primary Examiner. 

1. AN END CLOSURE FOR A COLLAPSIBLE CARTON, THE CARTON HAVING TUBULARLY ARRANGED SIDE AND END WALL PANELS WITH THE END CLOSURE CONNECTED TO ONE END THEREOF, THE END CLOSURE INCLUDING A PAIR OF OPPOSED FLAPS EACH FOLDABLY CONNECTED TO A RESPECTIVE SIDE WALL PANEL AND WITH FREE EDGES OPPOSITE THE RESPECTIVE FOLD CONNECTIONS, SAID FREE EDGES BEING IN OVERLAPPING RELATION, ONE OF SAID FLAPS HAVING END EDGES IN FOLDABLY CONNECTED RELATION TO A PAIR OF BELLOWS FOLD MEMBERS WHICH ARE IN TURN FOLDABLY CONNECTED TO THE ADJACENT END WALL PANELS, THE BELLOWS FOLD MEMBERS DISPOSED IN FLATWISE EXTERIOR RELATION TO SAID ONE FLAP AND INCLUDING AN ANGULAR FOLD LINE THEREIN TERMINATING AT RESPECTIVE FREE EDGE POINTS, THE SECOND ONE OF SAID OPPOSED PAIR OF FLAPS DISPOSED WITH MARGINAL PORTIONS ADJACENT THE FREE EDGE INTERVENING THE FIRST AND SECOND PORTIONS OF THE BELLOWS FOLD MEMBERS TO SECURE THE BOTTOM CLOSURE FROM OUTWARD EXTENSION. 